Apparatus for treating garbage and the like waste materials



ly 15, 1947. K. PETERSEN 2,423,994 APPARATUS FOR TREATING GARBAGE AND THE LIKE WASTE MATERIALS Filed Dec. 27, 1939 3 Sheets-Sheet l Lin/@7245" July 15, 1947. K. PETERSEN 2,423,994

APPARATUS FOR TREATING GARBAGE AND THE LIKE WASTE MATERIALS Filed Dec. 27, 1939 s Sheets-Sheet 2 1947. PETERSEN 7 2,423,994 I APPARATUS 'FOR TREATING GARBAGE AND THE LIKE WASTE MATERIALS Filed Dec. 27, 1939 3 Sheets-Sheet 3 10000000: 50000 .}OOOOOOO: ;O .0000 10 0000 0. ;0000 10000000; 000

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Patented July 15, 1947 APPARATUS FOR TREATING GARBAGE AND THE LIKE WASTE MATERIALS Kai Petersen, Soborg, near Copenhagen,

Denmark Application December 27, 1939, Serial No. 311,189 In Great Britain January 19, 1939 Claims.-

My present invention relates to an apparatus for treating garbage and the like waste materials containing difficultly grindable and/or nongrindable components.

More particularly, my invention constitutes an improvement in the apparatus described in my copending application Serial No. 261,631 filed March 3, 1939, and which became Patent No. 2,252,520 on August 12, 1941. In thisapparatus garbage is converted into a substantially homogeneous, granular and fibrous mass by treatin the grabage in rotary grinding drums containing one or more grinding chambers, the circumferential walls of which are constructed as a grid or a coarse screen surrounded by a finer screen having a mesh determining the fineness of the sufficiently ground material. At the same time a waste product is produced which consists of the diiilcultly grindable and/or non-grindable com-. ponents of the garbage and which is referred to in the following as the waste or remnants.

The main object of my present invention is to provide an apparatus in which it is possible to bring the coarse matter of the waste or remnants out of the grinding chamber or chambers without affecting the useful operation of the apparatus and to govern the movement and travel of the waste and the other components through the apparatus.

Broadly speaking, this object is accomplished by providing in the coarse screen or grid forming the circumferential walls of the grinding chamber one or more apertures being larger than the normal openings of the said coarse screen or grid and allowing the coarse matter of the waste or remnants to leave the grinding chamber when occasionally meeting the said apertures. In other words, the coarse matter of the waste slips through the grid-or coarse screen when the opportuni-ty presents itself, In order to distinguish the normal openings of the grid or coarse screen from the large apertures thereof through which the coarse matter of the waste or remnants slips, the latter will be referred to in the following as the slipping apertures.

A clear conception of the improvements according to my invention may be had by the following description containing a detailed explanation of my invention with reference to the accompanying drawings illustrating by way of example various preferred embodiments of apparatus and wherein:

Figure 1 is partly an elevation and partly a longitudinal sectional'view of one embodiment.

Figure 2 is a cross-sectional view of the same on line II-II of Fi ure 1.

Figures 3 and 4am developed views on an enlarged scale of one of the grid sections of the grinding-chambers provided with slipping apertures of a modified construction.

Figure 5 is a cross-sectional view of another embodiment, the said view corresponding to that shown in Figure 2.

Figure 6 is a similar view as those shown in Figures 3 and 4 of a further embodiment in which the circumferential walls of the grinding chambers are constructed as a coarse screen.

The apparatus shown in Figures 1 and 2 comprises a rotatable grinding drum having two end plates l and 3. A hollow trunnion 5 is secured to the end plate I and journalled in a bearing 1. A toothed ring 9 is also secured to the end plate I and adapted to be driven by 'a pinion not shown. Connecting braces or spider arms ll make the construction sufficiently rigid. Instead of the ring 9 a pulley may be secured to the end plate I so that the drum may be belt driven.

To the other end plate 3 there is secured a bearing ring 13 which rests on rollers l5, one of which is shown in Figure 1. The rollers 15 are journalled in bearings H. The end plate 3 is provided with a central aperture l9 receiving the lower part of a stationary hopper 2|.

The grinding drum is divided into two grinding chambers or compartments 23 and 25, respectively, by means of an elevating device 21 which is rigidly secured to double channel irons 29 being equidistantly spaced circumferentially and secured at their ends to the end plates I and 3, respectively. Together with angularly bent grid bars 31 spaced and secured to the inner flanges of the said channel irons, the channel irons form the circumferential walls of each grinding chamber 23 and 25, the said walls thereby constituting a grid provided with stepped surfaces the normal openings of the said grid having such a size as will prevent the coarse, difficultly grindable and/or non-grindable components of the garbage forming the waste or remnant from leaving the grinding chambers. Thus, the circumferential walls of the grinding chambers have the form of a grid divided by the channel irons 29 into sections the number of which depends on the number of channel irons. In Figures 1 and 2 each grinding chamber contains 12 grid sections.

At various places of the grinding chamber 23 the grid bars 3| are arranged with relatively large spaces forming larger apertures 22 through which the coarse matter of the waste or remnants may slip. The same applies to the grinding chamber 25 in which the slipping apertures are indicated by 24.

Both grinding chambers 23 and 25 are surrounded by conical screens or sieves 33 having a mesh determining the fineness of the sufficiently ground material and being finer than that of the grid forming the circumferential walls of the grinding drum. Hereinafter they will be referred to as fine sieves although they are only relatively fine, having for instance a width of about fine sieves 33 facilitates the screening action and prevents clogging of the fine sieves.

Although I have obtained excellent results with the construction and arrangement of the slipping apertures shown in Figure 1 my invention is not restricted to this construction and arrangement particularly in view of the fact that the construction and arrangement of the slipping apertures largely depend on the character of the garbage to be treated.

For instance, the slipping apertures need not extend into the whole length of the grid sections. This is illustrated in Figures 3 and 4.

InFigure 3 the central portion of some of the grid'bars 3| is removed so as to provide slipping apertures 22'. The ends of the bars 3| are secured to transversely extending bars 3| which at their ends are secured to the continuously extending grid bars 3|. Instead of being arranged in the middle of a section the slipping apertures 22 may be provided adjacent to the channel irons 29 for instance such as indicated at the bottom of Figure 3.

In Figure 4 each section only contains one slipping aperture 22" which is provided in a similar manner as in Figure 3, but with its largest proportion in the longitudinal direction of the grinding drum in contradistinction to the slipping apertures 22'. Also the slipping aperture 22" may be arranged at different places in adjacent sections, for'instance such as indicated.

By substituting some of the slipping apertures 22 of the grinding chamber 23 of the apparatus shown in Figure 1 by the slipping apertures shown in Figure 3 and/or 4 a grinding chamber is obtained which contains slipping apertures of difrent size. If desired, the lipping apertures may also be arranged in groups instead of being spaced as shown in Figure 1 or some of them may be spaced and others arranged in groups.

In the apparatus shown in Figures 1 to 4 the slipping apertures are permanent. They may, however, also be so constructed that they are adjustable in that they may be either diminished or removed. This is illustrated in Figure 5 showing a cross-section of an apparatus otherwise constructed as that shown in Figures 1 and 2.

Some of the grid bars 3| are cut over at one end adjacent to the channel irons 29 and swingably mounted at the other end adjacent to the following channel iron 29 as indicated by 93. The free end of the grid bar thus formed is supported by a link 95 connected to a crank 99. By operating the said crank the grid bar may be turned into a position either in alignment with the adjacent grid bars or beneath the same. Both positions are shown in Figure 5.

In this or other similar manner obvious to those skilled in the art the size and number of the slipping apertures may be varied.

Instead of constructing the circumferential walls of the grinding chambers as a number of grid sections they may, as mentioned above, also be constructed as a coarse screen. This is illustrated in Figure 6.

Sections of coarse screen ID! are secured to the channel irons 29, for instance welded thereto, and provided with normal openings I09 having such a size as will prevent the coarse, difilcultly grindable and/or non-grindable components of the garbage from leaving the grinding chamber but allow the fine and sufficiently ground matter together with partly ground material to pass. At various places larger apertures III are provided acting as slipping apertures through which the coarse matter of the waste or remnants may leave the grinding chamber when the said matter occasionally meets the slipping apertures during the rotation of the apparatus.

Generally, I prefer to construct the circumferential walls of the grinding chambers as grids. The size of the normal openings of the grids depends on the character of the garbage to be treated and may be determined by experimental work considering the period of time to be used for grinding the material and for performing the screening action due regard also being paid to the. composition of the material leaving the grinding chamber for screening on the fine sieves, to the number of times the material has to pass through the grid-shaped grinding surface for screening, and to the prevention of clogging of the grinding surface. I have found that in order to obtain a successful operation of the apparatus the normal openings of the grid may preferably have a length of about 600 to 700 millimetres and a width of about 18 to 30 millimetres while the useful sifting orscreening area of the grid represents about 25 to of the whole grinding surface. With the construction of the grid the coarse matter of the waste or remnants will not be able to pass the grid without providing slipping apertures. The length of the slipping apertures may be the same as that of the normal openings, pref erably somewhat smaller while the width of the said apertures is preferably about 40 to '70 millimetres, their area in the highest representing 50%, preferably 10-30%, of the whole useful area of the grid. Moreover, as a general rule, it is not appropriate to provide slipping apertures adjacent to the places of the grinding chamber where material is returned to the said chamber,

I am aware that many changes may be made in the construction of the apparatus described above and as illustrated on the drawings while still retaining the general principles of my invention. Hence I do not limit my invention to the exact arrangements and construction of parts, as described in the foregoing specification, nor do I confine myself to the exact details of construction of the various parts as illustrated on the accompanying drawings.

I claim:

1. In an apparatus of the ball mill type for grinding garbage and the like waste materials, a rotary grinding chamber, a coarse screen forming the circumferential walls of the said chamber and acting as the grinding surface of the chamber, the said screen having a plurality of openings of such a size as will prevent the coarse, diflicultly grindable and non-grindable components of the garbage from leaving the grinding chamber and in addition thereto having a considerably smaller number of large apertures arranged within the field of and being larger than the first mentioned openings of the screen, said apertures allowing the coarse, difficultly grindable and non-grindable components to leave the grinding chamber when they by chance meet with the said apertures and a fine screen for screening the material passing through the coarse screen, said fine screen having a mesh determining the fineness of the sufficiently ground material.

2. An apparatus as claimed in claim 1, in which the large apertures are of different size.

3. An apparatus as claimed in claim 1, in which the large apertures are spaced.

4. An apparatus as claimed in claim 1, in which the large apertures are arranged in groups.

5. In an apparatus of the ball mill type for grinding garbage and the like waste materials, a rotary grinding chamber, a coarse grid forming the circumferential walls of the'said-chamber and acting as the grinding surface of the chamber, the said grid having a plurality of openings of such a size as will prevent the coarse, difiicultly grindable and non-grindable components of the garbage from leaving the grinding chamber and in addition thereto having a considerably smaller number of large apertures arranged Within the field of and being larger than the first mentioned openings of the grid, said apertures allowing the coarse, difficultly grindable and non-grindable components to leave the grinding chamber when they by chance meet with the said apertures and a fine screen for screening the material passing through the coarse grid, said fine screen having a mesh determining the fineness of the sufficiently ground material.

6. An apparatus as claimed in claim 5, in which the large apertures are of diiferent size.

7. An apparatus as claimed in claim 5, in which the large apertures are spaced.

'8. An apparatus as claimed in claim 5, in which the large apertures are arranged in groups.

9. In an apparatus of the ball mill type for grinding garbage and the like waste materials, a rotary grinding chamber, a coarse screen forming the circumferential walls of the said chamber the said screen having a plurality of openings of such a size as will prevent the coarse, difiicultly grindable and non-grindable components of the garbage from leaving the grinding chamber, and in addition thereto having a considerably smaller number of large apertures arranged within the field of and being larger than the first mentioned openings of the screen said aperture allowing the coarse, diiiicultly grindable and non-grindable components to leave the grinding chamber when they by chance meet with the said apertures, a fine screen surrounding the grinding chamber and having a mesh determining the fineness of the sufficiently ground material, a casing secured to the grinding chamber and rotating therewith said casing having circumferential inlet openings communicating with the interior of the fine screen and pairs of outlet openings one outlet opening of each pair communicating with the interior of the grinding chamber while the other outlet opening of the same pair opens to the exterior of the said chamber, each pair of outlet openings being spaced from the axis of the rotary grinding chamber and so arranged as to be in a position above the axis of rotation of the grinding chamber when the corresponding inlet opening is in its uppermost position, a plurality of passages within the said casing each connecting an inlet opening of the casing with one pair of outlet openings thereof, a shiftable member arranged within and revolving with the casing and adapted to deliver the materials supplied to the casing by the fine screen to either of the outlet openings, the position of the said member determining to which of the outlet openings the materials are delivered, and a shaft secured to the said member and arranged to be operated from the outside of the casing.

10. In an apparatus of the ball mill type for grinding garbage and the like waste materials, a rotary rinding chamber having a front end plate with at least one inlet opening for supply of the materials to be ground and a rear end plate, spaced channel irons connecting the front end plate with the rear end 'plate and secured to the said plate at the circumference thereof, spaced grid bars extendin between adjacent channel irons and secured thereto, two adjacent channel irons and the grid bars between the said channel irons forming a grid section, the plurality of grid bars within the said section being arranged with such a space as will prevent the coarse, difficulty grindable and non-grindable components within the grinding chamber to leave the same, a number of grid bars within the said section each of which :being swingably mounted at one end adjacent to a channel iron while :the other end thereof adjacent to the following channel iron is free, means for supporting the free end of the grid bar to keep the said bar in alignment with the adjacent bars and means for moving the supporting means into a position in which the free end of the grid bar is arranged beneath the adjacent bars to provide a large aperture through which the coarse, difficult grindable and nongrindable components may pass when they by chance meet with the saidaperture.

11. In an apparatus of the ball mill type for grinding garbage and the like waste materials, a rotary grinding chamber, a coarse grid forming the circumferential walls of the said chamber the said grid having a plurality of openings of such a size as will prevent the coarse, difiicultly grindable and non-grindable components of the garbage from leaving the grinding chamber, and in addition thereto having a considerably smaller number of large apertures arranged within the field'of and being larger than the first mentioned openings of the grid said apertures allowing the coarse, diific'ultly grindable and non-grindable components to leave the grinding chamber when they by chance meet with the said apertures, a fine screen surrounding the grinding chamber and having a mesh determining the fineness of the sufiiciently ground material, an elevating device rotating with the grinding chamber, the said device having circumferential openings communicating with the interior of the fine screen and at least one pair of outlet openings one outlet opening of the said pair communicating with the interior of the grinding chamber while the other outlet opening of the same pair opens to the exterior'of the said'chamber, adjustable 'means arranged within and rotating with the elevating device and adapted to deliver the materials supplied to the said 'd'eviceb-y the fine screen to either of the outlet openings of the elevating device the position of the said adjustable means determining to which of the outlet openings the materials are delivered, and a shaft secured to the adjustable means and arranged to be operated from the outside of the elev'ating device.

12. In an-apparatus of the ball mill type for grinding garbage and the like Waste materials, a rotary grinding chamber, a coarse grid forming the circumferential walls of the said chamber the said grid having a plurality of openings of such asize as will prevent the coarse, 'difiicultly grindable and non-grindable components of the garbage from leaving the grinding chamber and in addition thereto having a considerably smaller number of'large apertures arranged within the field of'and "being "larger than the first-mentioned openings of the grid said 'apera'tures a1- lowing the coarse, di'fficultly grindable and nongrindab'le components to leave the grinding chamber when they :by chance .meet with the said apertures, a fine screen surrounding -'the grinding chamber and having a mesh determining the fineness of the sufficiently ground maspaced from terial, a casing secured to the grinding chamber and rotating therewith said casing havin circumferential inlet openings communicating with the interior of the fine screen and pairs of outlet openings one outlet opening of each pair communicating with the interior of the grinding chamber while the other outlet opening of the same pair opens to the exterior of the said chamber, each pair of outlet openings being the axis of the rotary grinding chamber and so arranged as to be in a position above the axis of rotation of the grinding chamber when the corresponding inlet opening is in its uppermost position, a plurality of passages within the said casing each connecting an inlet opening of the casing with one pair of outlet openings thereof, a shiftable member arranged within and revolving with the casing and adapted to deliver the materials supplied to the casing by the fine screen to either of the outlet openings, the position of the said member determining to which of the outlet openings the materials are delivered, and a shaft secured to the said member and arranged to be operated from the outside of the casing.

13. In an apparatus of the ball mill type for grinding garbage and the like waste materials, a rotary grinding chamber having a front end plate with at least one inlet opening for supply of the materials to be ground and a rear end plate, spaced channel irons connecting the front end plate with the rear end plate and secured to the said plates at the circumference thereof, spaced grid bars extending between adjacent channel irons and secured thereto, two adjacent channel irons and the grid bars secured thereto forming a grid section, the plurality of grid bars within the said section being arranged with such a space as will prevent the coarse, difficulty grindable and non-grindable components of the materials within the grinding chamber to leave the same whereas a smaller number of grid bars within the same section are arranged with a larger space forming large apertures through which the said coarse components may slip when they by chance meet with the said apertures.

14. In an apparatus of the ball mill type for grinding garbage and the like waste materials, a rotary grinding chamber, a coarse screen forming the circumferential walls of the said chamber and acting as the grinding surface of the chamber, the said screen having a plurality of openings of such a size as will prevent the coarse, difficultly grindable and non-grindable components of the garbage from leaving the grinding chamber and in addition thereto having a considerably smaller number of large apertures being larger than the firstmentioned openings of the screen said apertures allowing the coarse, difilcultly grindable and non-grindable components to leave the grinding chamber when they by chance meet with the said apertures and a fine screen for screening the material passing through the coarse screen said fine screen having a mesh determining the fineness of the sufficiently ground material.

15. In an apparatus of the ball mill type for grinding garbage and the like waste materials, a rotary grinding chamber, a coarse grid forming the circumferential walls of the said chamber and acting as the grinding surface of the chamber, the said grid having a plurality of openings of such a size as will prevent the coarse, difficultly grindable and non-grindable components of the garbage from leaving the grinding chamber and in addition thereto having a considerably smaller number of large apertures being larger than the firstmentioned openings of the grid said apertures allowing the coarse, difficultly grindable and non-grindable components to leave the grinding chamber when they by chance meet with the said apertures and a fine screen for screening the material passing through the coarse grid said fine screen having a mesh determining the fineness of the sufficiently ground material.

KAI PETERSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 253,380 Hawley Feb. 7, 1882 725,642 Ash Apr. 14, 1903 255,325 Oastler Mar. 21', 1882 441,951 Goetz Dec. 2, 1390 1,753,685 Bodenstein Apr. 8, 1930 737,750 Lindhard Sept. 1, 1903 694,974 Lindhard Mar. 11, 1902 1,619,145 McMillan Mar. 1, 1927 

